Tài liệu Introduction to Java: 22 java.awt.image Reference docx

setPixels public void setPixels int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize Parameters x x-coordinate of top-left corner of pixel data delivered wi

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// Instance Methods public void setHints (int hints);

public void setPixels (int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize);

public void setPixels (int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize);

}

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AreaAveragingScaleFilter

public AreaAveragingScaleFilter (int width, int height)

Parameters width Width of scaled image

height Height of scaled image

Description Constructs an AverageScaleFilter that scales the original

image to the specified size

Instance Methods

setHints

public void setHints (int hints)

Parameters hints Flags indicating how data will be delivered.Overrides ImageFilter.setHints(int)

Description Gives this filter hints about how data will be delivered

setPixels

public void setPixels (int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize)

Parameters x x-coordinate of top-left corner of pixel data

delivered with this method call

y y-coordinate of top-left corner of pixel data

w Width of the rectangle of pixel data delivered

with this method call

h Height of the rectangle of pixel data delivered

model Color model of image data

pixels Image data

off Offset from beginning of the pixels array

scansize Size of each line of data in pixels array

Overrides ReplicateScaleFilter.setPixels(int, int, int,

int, ColorModel, byte[], int, int)Description Receives a rectangle of image data from theImageProducer;

scales these pixels and delivers them to anyImageConsumers

public void setPixels (int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize)

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w Width of the rectangle of pixel data delivered

h Height of the rectangle of pixel data delivered

pixels Image data

off Offset from beginning of the pixels array

Overrides ReplicateScaleFilter.setPixels(int, int, int,

int, ColorModel, int[], int, int)Description Receives a rectangle of image data from theImageProducer;

scales these pixels and delivers them to anyImageConsumers

See Also

ColorModel, ReplicateScaleFilter

22.2 ColorModel Description

The abstractColorModel class defines the way a Java program represents colors

It provides methods for extracting different color components from a pixel

Class Definition

public class java.awt.image.ColorModel extends java.lang.Object {

// Variables protected int pixel_bits;

// Constructors public ColorModel (int bits);

// Class Methods public static ColorModel getRGBdefault();

// Instance Methods public void finalize(); ★

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public abstract int getGreen (int pixel);

public int getPixelSize();

public abstract int getRed (int pixel);

public int getRGB (int pixel);

}

ProtectedVariables

pixel_bits

protected int pixel_bits

Thepixel_bitsvariable saves the ColorModel’sbitssetting (the total ber of bits per pixel)

num-Constructors

ColorModel

public ColorModel (int bits)

Parameters bits The number of bits required per pixel using this

model

Description Constructs aColorModelobject

Class Methods

getRGBdefault

public static ColorModel getRGBdefault()

Returns The defaultColorModelformat, which uses 8 bits for each of a

pixel’s color components: alpha (transparency), red, green,and blue

finalize

Overrides Object.finalize()Description Cleans up when this object is garbage collected

getAlpha

public abstract int getAlpha (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current alpha setting of the pixel

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public abstract int getBlue (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current blue setting of the pixel

getGreen

public abstract int getGreen (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current green setting of the pixel

getPixelSize

public int getPixelSize()

Returns The current pixel size for the color model

getRed

public abstract int getRed (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current red setting of the pixel

getRGB

public int getRGB (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current combined red, green, and blue settings of the

TheCropImageFilterclass creates a smaller image by cropping (i.e., extracting

a rectangular region from) a larger image

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public class java.awt.image.CropImageFilter extends java.awt.image.ImageFilter {

// Constructors public CropImageFilter (int x, int y, int width, int height);

// Instance Methods public void setDimensions (int width, int height);

public void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize);

public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize);

public void setProperties (Hashtable properties);

Parameters x x-coordinate of top-left corner of piece to crop

y y-coordinate of top-left corner of piece to crop

width Width of image to crop

height Height of image to crop

Description Constructs aCropImageFilterthat crops the specified region

from the original image

setDimensions

public void setDimensions (int width, int height)

Parameters width Ignored parameter

height Ignored parameter

Overrides ImageFilter.setDimensions(int, int)Description Called with the original image’s dimensions; these dimensions

are ignored The method in turn calls the ImageConsumerwith the dimensions of the cropped image

setPixels

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public void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize)

width Width of the rectangle of pixel data delivered

height Height of the rectangle of pixel data delivered

pixels Image data

offset Offset from beginning of the pixels array

Overrides ImageFilter.setPixels(int, int, int, int,

ColorModel, byte[], int, int)Description Receives a rectangle of image data from theImageProducer;

crops these pixels and delivers them to anyImageConsumers

public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)

pixels Image data

Overrides ImageFilter.setPixels(int, int, int, int,

ColorModel, int[], int, int)Description Receives a rectangle of image data from theImageProducer;

crops these pixels and delivers them to anyImageConsumers

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public void setProperties (Hashtable properties)

Parameters properties The properties for the image

Overrides ImageFilter.setProperties(Hashtable)Description Adds the “croprect” image property to the properties list

See Also

ColorModel,Hashtable,ImageFilter

22.4 DirectColorModel Description

TheDirectColorModelclass provides aColorModel that specifies a translationbetween pixels and alpha, red, green, and blue component values, where the colorvalues are embedded directly within the pixel

public class java.awt.image.DirectColorModel extends java.awt.image.ColorModel {

// Constructors public DirectColorModel (int bits, int redMask, int greenMask, int blueMask);

public DirectColorModel (int bits, int redMask, int greenMask, int blueMask,

int alphaMask);

// Instance Methods public final int getAlpha (int pixel);

public final int getAlphaMask();

public final int getBlue (int pixel);

public final int getBlueMask();

public final int getGreen (int pixel);

public final int getGreenMask() public final int getRed (int pixel);

public final int getRedMask();

public final int getRGB (int pixel);

}

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DirectColorModel

public DirectColorModel (int bits, int redMask, int greenMask, int blueMask)

Parameters bits The number of bits required per pixel of an

image using this model

redMask The location of the red component of a pixel

greenMask The location of the green component of a pixel

blueMask The location of the blue component of a pixel.Throws IllegalArgumentException

If the mask bits are not contiguous or overlap.Description Constructs a DirectColorModel object with the given size

and color masks; the alpha (transparency) component is notused

public DirectColorModel (int bits, int redMask, int greenMask, int blueMask, int alphaMask)

Parameters bits The number of bits required per pixel of an

image using this model

redMask The location of the red component of a pixel

greenMask The location of the green component of a pixel

blueMask The location of the blue component of a pixel

alphaMask The location of the alpha component of a pixel.Throws IllegalArgumentException

If the mask bits are not contiguous or overlap.Description Constructs a DirectColorModel object with the given size

and color masks

getAlpha

public final int getAlpha (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current alpha setting of the pixel

Overrides ColorModel.getAlpha(int)

getAlphaMask

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public final int getAlphaMask()

Returns The current alpha mask setting of the color model

getBlue

public final int getBlue (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current blue setting of the pixel

Overrides ColorModel.getBlue(int)

getBlueMask

public final int getBlueMask()

Returns The current blue mask setting of the color model

getGreen

public final int getGreen (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current green setting of the pixel

Overrides ColorModel.getGreen(int)

getGreenMask

public final int getGreenMask()

Returns The current green mask setting of the color model

getRed

public final int getRed (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current red setting of the pixel

Overrides ColorModel.getRed(int)

getRedMask

public final int getRedMask()

Returns The current red mask setting of the color model

getRGB

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public final int getRGB (int pixel)

Parameters pixel A pixel encoded with thisColorModel.Returns The current combined red, green, and blue settings of the

pixel

Overrides ColorModel.getRGB(int)Description Gets the color ofpixelin the default RGB color model

See Also

ColorModel

22.5 FilteredImageSource Description

TheFilteredImageSourceclass acts as glue to put an originalImageProducerandImageFiltertogether to create a new image As theImageProducerfor thenew image, FilteredImageSource is responsible for registering image con-sumers for the new image

// Instance Methods public synchronized void addConsumer (ImageConsumer ic);

public synchronized boolean isConsumer (ImageConsumer ic);

public synchronized void removeConsumer (ImageConsumer ic);

public void requestTopDownLeftRightResend (ImageConsumer ic);

public void startProduction (ImageConsumer ic);

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Parameters original AnImageProducerthat generates the image to

be filtered

filter TheImageFilterto use to process image data

delivered byoriginal.Description Constructs a FilteredImageSource object to filter an image

generated by anImageProducer

Class Methods

addConsumer

public synchronized void addConsumer (ImageConsumer ic)

Parameters ic ImageConsumerinterested in receiving the new

image

Implements ImageProducer.addConsumer(ImageConsumer)Description Registers an ImageConsumer as interested in Image

information

isConsumer

public synchronized boolean isConsumer (ImageConsumer ic)

Parameters ic ImageConsumerto check

Returns true if ImageConsumer is registered with this

ImagePro-ducer,falseother wise

Implements ImageProducer.isConsumer(ImageConsumer)

removeConsumer

public synchronized void removeConsumer (ImageConsumer ic)

Parameters ic ImageConsumerto remove

Implements ImageProducer.removeConsumer(ImageConsumer)Description Removes an ImageConsumer from the registered consumers

for thisImageProducer

left-to-right order

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public void startProduction (ImageConsumer ic)

Parameters ic ImageConsumerto communicate with

Implements ImageProducer.startProduction(ImageConsumer)Description RegistersImageConsumer as interested in Imageinformation

and tells ImageProducer to start creating the filteredImagedata immediately

See Also

ImageFilter,ImageConsumer,ImageProducer,Object

22.6 ImageConsumer Description

ImageConsumer is an interface that provides the means to consume pixel dataand render it for display

Interface Definition

public abstract interface java.awt.image.ImageConsumer {

// Constants public final static int COMPLETESCANLINES;

public final static int IMAGEABORTED;

public final static int IMAGEERROR;

public final static int RANDOMPIXELORDER;

public final static int SINGLEFRAME;

public final static int SINGLEFRAMEDONE;

public final static int SINGLEPASS;

public final static int STATICIMAGEDONE;

public final static int TOPDOWNLEFTRIGHT;

// Interface Methods public abstract void imageComplete (int status);

public abstract void setColorModel (ColorModel model);

public abstract void setDimensions (int width, int height);

public abstract void setHints (int hints);

public abstract void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize);

public abstract void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize);

public abstract void setProperties (Hashtable properties);

}

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COMPLETESCANLINES

public final static int COMPLETESCANLINES

Hint flag for the setHints(int) method; indicates that the image will bedelivered one or more scanlines at a time

IMAGEABORTED

public final static int IMAGEABORTED

Status flag for theimageComplete(int)method indicating that the loadingprocess for the image aborted

IMAGEERROR

public final static int IMAGEERROR

Status flag for the imageComplete(int) method indicating that an errorhappened during image loading

RANDOMPIXELORDER

public final static int RANDOMPIXELORDER

Hint flag for the setHints(int) method; indicates that the pixels will bedelivered in no particular order

SINGLEFRAME

public final static int SINGLEFRAME

Hint flag for thesetHints(int)method; indicates that the image consists of

a single frame

SINGLEFRAMEDONE

public final static int SINGLEFRAMEDONE

Status flag for theimageComplete(int)method indicating a single frame ofthe image has loaded

SINGLEPASS

public final static int SINGLEPASS

Hint flag for thesetHints(int) method; indicates that each pixel will bedelivered once (i.e., the producer will not make multiple passes over theimage)

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public final static int STATICIMAGEDONE

Status flag for theimageComplete(int) method indicating that the imagehas fully and successfully loaded, and that there are no additional frames

TOPDOWNLEFTRIGHT

public final static int TOPDOWNLEFTRIGHT

Hint flag for thesetHints(int)method; indicates that pixels will be ered in a top to bottom, left to right order

deliv-Interface Methods

imageComplete

public abstract void imageComplete (int status)

Parameters status Image loading status flags

Description Called when the image, or a frame of an image sequence, is

complete to report the completion status

setColorModel

public abstract void setColorModel (ColorModel model)

Parameters model The color model for the image

Description Tells theImageConsumerthe color model used for most of the

pixels in the image

setDimensions

public abstract void setDimensions (int width, int height)

Parameters width Width for image

height Height for image

Description Tells the consumer the image’s dimensions

setHints

public abstract void setHints (int hints)

Parameters hints Image consumption hints

Description Gives the consumer information about how pixels will be

deliv-ered

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public abstract void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize)

pixels Image data

Description Delivers a rectangular block of pixels to the image consumer

public abstract void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)

pixels Image data

Description Delivers a rectangular block of pixels to the image consumer

setProperties

public abstract void setProperties (Hashtable properties)

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Description Delivers a Hashtable that contains the image’s properties.

See Also

ColorModel,Hashtable,ImageFilter,PixelGrabber,Object

22.7 ImageFilter Description

TheImageFilterclass sits between theImageProducerandImageConsumeras

an image is being created to provide a filtered version of that image Image filtersare always used in conjunction with aFilteredImageSource As an implementer

of theImageConsumerinter face, an image filter receives pixel data from the inal image’s source and delivers it to another image consumer TheImageFilterclass implements a null filter (i.e., the new image is the same as the original); toproduce a filter that modifies an image, create a subclass ofImageFilter

// Constructors public ImageFilter();

// Instance Methods public Object clone();

public ImageFilter getFilterInstance (ImageConsumer ic);

public void imageComplete (int status);

public void resendTopDownLeftRight (ImageProducer ip);

public void setColorModel (ColorModel model);

public void setDimensions (int width, int height);

public void setHints (int hints);

public void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize);

public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize);

public void setProperties (Hashtable properties);

}

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Protected Variables

consumer

protected ImageConsumer consumer

The consumer variable is a reference to the actualImageConsumer for theImage

getFilterInstance

public ImageFilter getFilterInstance (ImageConsumer ic)

Parameters ic The consumer in question

Returns A copy of theImageFilterinstance

Description Returns the filter that will do the filtering foric

imageComplete

void imageComplete (int status)

Parameters status Image loading completion status flags

Implements ImageConsumer.imageComplete(int)Description Called by theImageProducer to indicate an image’s comple-

tion status ImageFilter passes these flags to the consumerunchanged

resendTopDownLeftRight

public void resendTopDownLeftRight (ImageProducer ip)

Parameters ip The ImageProducer generating the original

image

Description Called by the ImageConsumer to ask the filter to resend the

image data in the top-down, left-to-right order In

Image-914 IMAGEFILTER

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void setColorModel (ColorModel model)

Parameters model The color model for the image

Implements ImageConsumer.setColorModel(ColorModel)Description Sets the image’s color model

setDimensions

void setDimensions (int width, int height)

Parameters width Width for image

height Height for image

Implements ImageConsumer.setDimensions(int, int)Description Sets the image’s dimensions

setHints

void setHints (int hints)

Parameters hints Image consumption hints

Implements ImageConsumer.setHints(int)Description Called by the ImageProducer to deliver hints about how the

image data will be delivered ImageFilterpasses these hints

on to theImageConsumer

setPixels

void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize)

pixels Image data

Implements ImageConsumer.setPixels(int, int, int, int,

ColorModel, byte[], int, int)

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Description Delivers a rectangular block of pixels to the ImageFilter.

ImageFilter passes these pixels on to the consumerunchanged

void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)

pixels Image data

Implements ImageConsumer.setPixels(int, int, int, int,

ColorModel, int[], int, int)Description Delivers a rectangular block of pixels to the ImageFilter

ImageFilter passes these pixels on to the consumerunchanged

setProperties

void setProperties (Hashtable properties)

Implements ImageConsumer.setProperties(Hashtable)Description Initializes the image’s properties.ImageFilteradds the prop-

erty “filter” to theHashtable, and passes the result on to theimage consumer; the value of the property is the stringreturned by the filter’s toString() method If the property

“filter” is already in the Hashtable, ImageFilter adds thestring returned by itstoString()method to the value alreadyassociated with that property

See Also

Cloneable,ColorModel,CropImageFilter,Hashtable,ImageConsumer,ImageProducer,Object,ReplicateImageFilter,RGBImageFilter

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22.8 ImageObserver Description

ImageObserver is an interface that provides constants and the callback nism to receive asynchronous information about the status of an image as it loads

mecha-Interface Definition

public abstract interface java.awt.image.ImageObserver {

// Constants public static final int ABORT;

public static final int ALLBITS;

public static final int ERROR;

public static final int FRAMEBITS;

public static final int HEIGHT;

public static final int PROPERTIES;

public static final int SOMEBITS;

public static final int WIDTH;

// Interface Methods public abstract boolean imageUpdate (Image image, int infoflags, int x, int y, int width, int height);

}

Constants

ABORT

public static final int ABORT

TheABORTflag indicates that the image aborted during loading An attempt

to reload the image may succeed, unlessERRORis also set

ALLBITS

public static final int ALLBITS

TheALLBITSflag indicates that the image has completely loaded successfully.The x, y, width, and height arguments to imageUpdate() should beignored

ERROR

public static final int ERROR

The ERROR flag indicates that an error happened during the image loadingprocess An attempt to reload the image will fail

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public static final int FRAMEBITS

TheFRAMEBITS flag indicates that a complete frame of a multi-frame imagehas loaded The x, y, width, and height arguments to imageUpdate()should be ignored

HEIGHT

public static final int HEIGHT

The HEIGHT flag indicates that the height information is available for animage; the image’s height is in theheightargument toimageUpdate()

PROPERTIES

public static final int PROPERTIES

ThePROPERTIESflag indicates that the properties information is available for

an image

SOMEBITS

public static final int SOMEBITS

TheSOMEBITSflag indicates that the image has started loading and some els are available The bounding rectangle for the pixels that have been deliv-ered so far is indicated by the x, y, width, and height arguments toimageUpdate()

pix-WIDTH

public static final int WIDTH

TheWIDTHflag indicates that the width information is available for an image;the image’s width is in thewidthargument toimageUpdate()

Interface Methods

imageUpdate

public abstract boolean imageUpdate (Image image, int infoflags, int x, int y, int width, int height)

Parameters image Image that is being loaded

infoflags The ImageObserver flags for the information

that is currently available

x Meaning depends oninfoflagsthat are set

y Meaning depends oninfoflagsthat are set

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width Meaning depends oninfoflagsthat are set.

height Meaning depends oninfoflagsthat are set.Returns true if image has completed loading (successfully or unsuc-

cessfully),falseif additional information needs to be loaded.Description Provides the callback mechanism for the asynchronous loading

of images

See Also

Component,Image,Object

22.9 ImageProducer Description

ImageProduceris an interface that provides the methods necessary for the duction of images and the communication with classes that implement theImageConsumerinter face

pro-Interface Definition

public abstract interface java.awt.image.ImageProducer {

// Interface Methods public abstract void addConsumer (ImageConsumer ic);

public abstract boolean isConsumer (ImageConsumer ic);

public abstract void removeConsumer (ImageConsumer ic);

public abstract void requestTopDownLeftRightResend (ImageConsumer ic); public abstract void startProduction (ImageConsumer ic);

}

Interface Methods

addConsumer

public abstract void addConsumer (ImageConsumer ic)

Parameters ic AnImageConsumerthat wants to receive image

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public abstract boolean isConsumer (ImageConsumer ic)

Parameters ic ImageConsumerto check

Returns true if ImageConsumer has registered with the

ImagePro-ducer,falseother wise

removeConsumer

public abstract void removeConsumer (ImageConsumer ic)

Parameters ic ImageConsumerto remove

Description Removes an ImageConsumer from registered consumers for

thisImageProducer

requestTopDownLeftRightResend

public abstract void requestTopDownLeftRightResend (ImageConsumer ic)

Parameters ic ImageConsumerto communicate with

Description Requests the retransmission of the image data in top-down,

left-to-right order

startProduction

public abstract void startProduction (ImageConsumer ic)

Parameters ic ImageConsumer to communicate with

Description Registers ImageConsumer as interested in image information

and tells ImageProducer to start sending the image dataimmediately

See Also

FilteredImageSource,Image,ImageConsumer,ImageFilter,ageSource,Object

MemoryIm-22.10 IndexColorModel Description

TheIndexColorModelclass is aColorModelthat uses a color map lookup table(with a maximum size of 256) to convert pixel values into their alpha, red, green,and blue component parts

920 IMAGEPRODUCER

Tiêu đề	Introduction to Java: 22 java.awt.image Reference docx
Trường học	University of Example
Chuyên ngành	Computer Science
Thể loại	Giáo trình
Năm xuất bản	2002
Thành phố	Hà Nội

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Số trang	48
Dung lượng	133,79 KB